Comparison of PM exhaust Comparison of PM exhaust emissions measured at a emissions measured at a

chassis dynamometer and on-chassis dynamometer and on-road chasing road chasing

Rainer Vogt, Volker Scheer, Roberto CasatiFord Forschungszentrum Aachen GmbH

Barouch Giechaskiel, Zissis SamarasLAT, Aristotle University Thessaloniki

2

Overview

• Objectives of the study

• On-road chasing method Results of on-road chasing

• Laboratory experimental setup Results of chassis dyno work, comparison of instruments

• Comparison of lab and chasing

• Conclusions 

3

ObjectivesObjectives• To measure the PM emissions of the VW TDI by chasing the exhaust plume with the Ford Mobile Laboratory (FML) at three constant speeds and fixed distance on a test trace

• To measure the PM emissions of the VW TDI with the PARTICULATES dilution system at the FFA chassis dynamometer at the same constant speeds and during the NEDC

• To compare the results obtained with the PARTICULATES dilution system with real-world dilution measured during chasing the exhaust plume with a special focus on nucleation particles

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On-road chasing of exhaust plumeOn-road chasing of exhaust plume

Test vehicle:VW Golf TDI 1.9 l speed, fuel consumption EN590 diesel (280 ppm S)

Ford Mobile Lab:SMPS, CPC, NOx, CO2

T and RH

Test track: high speed oval, 4 km/lap14 m distance: 0.4 s (120 km h-1)

1 s (50 km h-1)

5

In-let for on-road sampling In-let for on-road sampling

• inlet: 4 mm (15 cm)• transfer line: 10.3 mm (420 cm)• total residence: 1.4 s

6

Constant speed tests

• T= 3-6 °C, RH= 50 - 55 % (February 2003)

• 10 min warm-up at 120 km h-1

• 8 min at 120, 100, 50 km h-1

1.0E+12

1.0E+13

1.0E+14

1.0E+15

1.0E+16

1.0E+17

10 100 1000

Mobility Diameter [nm]

Num

ber

emis

sion

rat

edN

/dlo

g(D

p) [k

m-1

] 120 km/h

100 km/h

50 km/h

7

Geometric Mean diameter

30

35

40

45

50

55

60

65

70

50 km/h 100 km/h 120 km/h

Geo

met

ric

mea

n di

amet

er [n

m]

8

Speed ramp tests

60

70

80

90

100

110

120

130

0 600 1200 1800 2400 3000

time / s

spee

d /

km h

-1

9

Speed ramp tests

1.0E+12

1.0E+13

1.0E+14

1.0E+15

1.0E+16

1.0E+17

10 100 1000

Mobility Diameter [nm]

Num

ber e

mis

sion

rate

dN/d

log(

Dp)

[km

-1]

90 km/h (1)

100 km/h (1)

110 km/h (1)

120 km/h

110 km/h (2)

100 km/h (2)

90 km/h (2)

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Comparison: Lab & On-road chasing

1.0E+12

1.0E+13

1.0E+14

1.0E+15

10 100 1000

Mobility diameter [nm]

Num

ber e

mis

sion

rate

dN/d

log(

Dp)

[km

-1]

chasing

PART.

Matter

• 50km h-1

• PFSS: PDR: 12.5 DT: 32°C LR

11

Laboratory experimental setup

Results of chassis dyno work

comparison of instruments

- Makis part -

12

Comparison: Lab & On-road chasing

1.0E+11

1.0E+12

1.0E+13

1.0E+14

1.0E+15

10 100 1000

Mobility diameter [nm]

Num

ber e

mis

sion

rate

dN/d

log(

Dp)

[km

-1]

chasing

PART. DT = 32°C LR

PART. DT = 32°C SR

PART. DT = 10°C SR

Matter

• 100km h-1

13

Comparison: Lab & On-road chasing

1.0E+12

1.0E+13

1.0E+14

1.0E+15

1.0E+16

1.0E+17

10 100 1000

Mobility diameter [nm]

Num

ber

emis

sion

rat

edN

/dlo

g(D

p) [k

m-1

]

chasing

PART. DT = 32°C LR

PART. DT = 32°C SR

PART. DT = 10°C SR

Matter

• 120km h-1

14

Conclusions (1)

• The PARTICULATES system is suitable to study the influence of the dilution parameters on nucleation

• Longer residence time favours the growth of the nucleation particles and shifts the nucleation mode to larger diameters

• Lower dilution air temperature enhances the formation of nucleation particles, with increased number and a distinct mode is formed at lower speed.

• Chasing and lab experiments show that nucleation is not stable in a time scale of several minutes; dependent on vehicle history as shown in speed ramp tests

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Conclusions (2)• The particle size distributions (only soot mode present)

measured during chasing at 50 km/h were in very good agreement with dynamometer measurements

• At about 100 km/h nucleation particles occur during the chasing experiment. The occurrence and in general the emission rate of these particles can be reproduced with the PARTICULATES system, if the dilution parameters are chosen in order to match the ambient conditions.

• At 120 km/h a strong nucleation mode is observed in the exhaust plume. While the PARTICULATES system is capable to reproduce the soot mode very well, it shows a nucleation mode, which is somewhat lower in particle number, but larger in diameter.

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- Back-up -

17

1.0E+12

1.0E+13

1.0E+14

1.0E+15

1.0E+16

10 100 1000

Mobility diameter [nm]

Num

ber e

mis

sion

rate

dN/d

log(

Dp)

[km

-1]

- 0,33 %

0 %

0,33 %

0,67 %

1 %

• 100 km h-1

• simulated % grade

Effect of chassis load

18

Effect of chassis load

1.0E+12

1.0E+13

1.0E+14

1.0E+15

1.0E+16

10 100 1000

Mobility diameter [nm]

Num

ber e

mis

sion

rate

dN/d

log(

Dp) [

km-1

]

- 0,5 %

0 %

0,5 %

1 %

1,5 %

• 120 km h-1

• simulated % grade